lewy-d wrote:So Alan, what would be a good target compression ration for a 454 TBI motorhome? If we are unable to come up with a set of the old 366 heads, are there any aluminum heads that could be used? Better question: what runner volume are we looking for? I'm not real big block savy. We use a 1990 flatnose motorhome to tow to & fro Bonneville. It really needs some help. we're hoping its a hyd. roller. If not It may get converted. 1 3/4" headers are ok? Get both sides together with a good merge to a 3"? 3 1/2?
Thanks for the help. I'm sure I'll have more questions.
DaveMcLain wrote:Gosh I built a 366 a few years ago for about an '89 Top Kick truck and it seems like it had TBI and the truck heads were not of the Peanut variety, maybe I'm mistaken. That engine did require a different intake gasket set than other big Chevy engines however because it had an extra coolant passage in the intake.
Alan Roehrich wrote:All the 366 engines around here came from school buses. None I have seen had passenger car sized oval ports. If you can a truck head for passenger car size intake valves, you'll need to put intake seats in it.
You cannot have too good an exhaust valve in a truck engine, that is true. There is no substitute for premium valves. That's also why I mentioned that I use natural gas seats when replacing seats. It's also a good application for a sodium filled exhaust valve.
lewy-d wrote:Thanks! Ok now we're starting to lock some things in! I doubt we'll add any stroke to it. mostly 'cause I think of a greater displacement = less economy. I'd like to keep it TBI. It may wind up on megasquirt later but at least the engine won't be a dog.
What intake do you think would be good with the 212/218 cam you recommend? I think it's got some room under there for something tall. Air gap?
are 1 7/8" headers too big? dual 3" eh? common case muffler or 2 seperate mufflers? X pipe? H pipe? If we don't find the budget for alum. heads what casting are we looking for from the 396 engine?
You work at Nitroplate? I've had quite a bit of stuff coated there. The motorhome in question is Daryl Whites' of RPM. He turned me on to you guys. In fact I have a manifold that needs coating soon. You're not the owner of the GTO are you?
coolchevy wrote:I'll go sequential with EFIconnection hardware and self ingenuity. What do you think about the Edelbrock ProFlow X intake for that application, i can use a stock Corvette C5 throttle body on it and have electronic cruise control too?
Alan Roehrich wrote:
Here's a thought. An inline two four barrel dual plane intake, with two 305 throttle bodies, or two 454 throttle bodies with 305 injectors. Plenty of airflow, better mixture distribution, and smaller injectors. I've seen it done, it works, it runs, fuel economy only changes if your foot causes it, Turbo City used to make the kit. The stock throttle body flows about 650, it is really plenty for a relatively low RPM RV/tow vehicle engine. I threw that in for the guys who might be looking at doing something more.